硫化物对GCr15轴承钢疲劳寿命的影响

Effect of Sulfur on Fatigue Life of GCr15 Bearing Steel

硫使钢产生“热脆”,异相夹杂物使钢基体产生嵌镶应力,对基体产生划伤、割裂作用,破坏机体的连续性.不同类型异相夹杂因其形状、性能、分布、线膨胀系数等的不同而对基体产生的影响迥异.硫化物夹杂因其塑性好、线膨胀系数大、对轴承钢疲劳寿命影响较小.对硬脆夹杂物有包裹作用而对轴承钢疲劳裂纹的产生、发展有一定阻碍作用.但在脆性夹杂物大幅度降低条件下,硫(硫化物杂夹)含量范围应当予以限制.

Sulfur brings the steel＇s “hot brittleness”. Heterophase inclusions produce inlaid stress to the matrix. Thus the matrix may be scuffed and dissevered, and the continuity of the matrix may be destroyed. The effect on the matrix varies with the inclusion. Thns shape, performance, distribution and coefficient of linear expansion. As sulfid has better plasticity and bigger coefficient of linear expansion, and it has less effect on fatigue life of bearing steel. The sulfid may have the function of enwrapping brittle inclusions, thus it is able to baffle the flaw in bearing steel. When the brittle inclusions are reduced to a great extent, the content of the sulfur （sulfide inclusions） should be restricted.